Grinding wheel



Dec. 22, 1964 w LINDBLAD 3,161,995

GRINDING WHEEL Filed Nov. 14. 1961 INVENTOR. FEoRcK W. LmoeLAo UnitedStates Parent Office &161395 Patented Dec. 272, 1964:

3,151,995 GRlNllNG WHEEL Fredericls W. Linrlhlad, 835 rllinois Ave.,Aurora, ill. Filed Nov. 14, 19631, Ser. No. 152319 7 Claims. (Ch 51-209)This invention relates in general to grinding and, more particularly, toa grinding wheel wherein an abrasive member that performs the grindingoperation is Secured to a body or core.

It is an object of the present invention to provide a grinding wheelwhich permits increased air cooling of the abrasive member and theinterfaces between the abrasive member and the body or core upon whichthe abrasive member is mounted. r

lt is a further andmore specific object of the present invention toprovide'a grinding wheel of the type stated in which the outer surfaceof the body or core has a plurality of air passageways which terminateat an interface between the abrasive member and body so that air movingalong the passageways can cool the abrasive member and the interfacebetween it and the body.

The attainment of the above and further objects of the present inventionwill be apparent from the following specification taken in conjnnctionwith the accompanying drawing forming a part thereof.

In the drawing:

FIG. l is a top plan view of a grinding wheel constructed in accordancewith and einbodying the present invention;

FlG. 2 is a sectional View taken along line 2-2 of FlG 1;

FlG. 3 is a bottom plan View of the grinding wheel;

FIG. 4 is a fragmentary sectional View, on an enlarged scale, takenalong line 4-4 of FG. 3; and

FlG. 5 is a fragmentary sectional view taken along line 5 5 of FIG. 4.

Reference may now be had to the drawing, which illustrates a preferredembodiment of the present invention, and wherein like referencecharacters designate like parts throughout.

l`he grinding wheel A comprises a core or body l which may be a ilaredcup-shaped member which, inthe broad aspects of this invention, may bemolded or otherwise formed of any desired material. Nylon has been foundto be a suitable material out of which to fabricate the body l becauseof the fact that nylon imparts a small amount of resiliency to the bodyl. However, other materials may be used in the fabrication of the body1, another preferred material being a phenolic molding compound, such asexplained in rny United States Patent 2,703,437 that issued March 8,1955. The body 1 may have any suitable shape, as, for example, thetrusto-conical shape shown. At its smaller diameter end, the body i hasa wall 3 which lies at rightangles to the central longitudinal axis a ofthe body and has a hole 5 for mounting the body upon the arbor of agrinding machine.

At its larger diameter end, the body l has a seat '7 which receives andsupports a frusto-conical grinding ring 9. The seat 7 may comprise ashoulder 11 formed on the exterior surface of the body 1 and lying atright angles to the axis a. The seat 7 also includes a fusto-conicalfiange 13 which extends from the shoulder 11 to the larger diameter endof the body l for receiving the internal frusto-conical surface of thegrinding ring 9. The larger diameter end of the flange 13 has aplurality of circumferentially spaced notches 15 which extend toward theshoulder ll whereby the fiange 13 may be bent inwardly, that is, towardthe central axis a to enable the grinding ring 9 to be slipped over theilange 13 and seat against the shoulder 11.

The grinding ring 9 is molded to the shape shown and may be of anyconventional type. One such type may be a ring having industrial diamondabrasive particles nolded within a body of plastic. When the grindingring 9 has been fabricated, it is assembled with the body l with abonding agent between the grincling ring 9 and the seat 7. Epoxy resinsare bonding agents suitable for this purpose.

Formed on the outer frusto-conical surface 17 of the body I arecircumferentially spaced slots 19 eachof which extend from the smallerdiameter end of the body 1 to the shoulder ll. In the form of theinvention shown, the body may be molded with the Slots 19 therein. Ithas been found that these Slots 19 form air passageways that increasethe air cooling of the grinding ring 9 and the body 1, and particularlythe interface between the two. The grinding wheel A is of a type whichis intended to be operated at a very high speed of rotation. For eX-ample, the linear speed at the outer periphery of the grinding ring 9may eXceed one mile per minute. At such high speeds, the rotatinggrinding wheel tends to drag with it a film of air which also moves at ahigh velocity but, of necessity, somewhat less than the velocity of thegrindng wheel. It is believed that this rotating air layer creates avacuum `at the surface 17 and in the slot 19 so that air may flow intothe slots lil and against the portions of the grinding ring at the endof each slot 19. This movement of air in the slots 19 will cool both thegrinding ring 9 and the interface between the grnding ring 9 and seat 7wherein the bonding resin is located. Consequently, the provision of airpassageways 19 on the surface of the body 1 helps to prevent adeterioration of the grinding ring 9 and the bonding agent at theinterface between the grinding ring 9 and body i, thereby increasing theservice life of the grinding wheel.

The inner frusto-conical surface 21 may, if desired, be provided withvanes 23 that act as fan blades and maintain a stream of air across theinner surface of the flange 13 and the portion of the innerfrusto-conical surface of the grindng ring 9 that is exposed at theSlots 19. This further facilitates cooling the grinding ring 9 and itsinterface with the body l.

When the body 1 is molded in accordance with the process of my priorUnited States Patent 2,703,437, which is within the concept of thepresent invention, the ring 9 may be molded in place at the same time,all as disclosed in my above patent.

ln compliance with the requirernents of the patent statutes I haveherein shown and described a preferred embodiment of the invention. ltis, however, to be under- I stood that the invention is not limited tothe precse con-. struction herein shown, the same being merelyillustrative of the principles of the invention. What is considered newand sought to be Secured by Letters Patent is:

l, A grinding wheel comprising a body having means for mounting same forrotation about the central longitudinal aXis of the body, means on saidbody forming a seat surrounding said aXis, and an abrasive member onsaid seat, the portion of the body that extends between the abrasivemember and the means for mounting the body being substantially a surfaceof revolution centered on said axis but deviating from a surface ofrevolution by having means for directing a flow of cooling air againstthe abrasive member, said ilow directing means compris ing Channels inthe surface of revolution and each channel extending to the juncture ofthe abrasive member with the body, and directing a flow of air towardsaid juncture for accentuating motion of cooling air at the region ofsaid juncture. i

2. A grinding wheel comprising a hollow frusto-conical body havin meansat'the smaller diameter end for i mounting the same for rotation aboutthe central longtudinal axis of the body, the larger diameter end of thebody having a radially extendng seat for a grinding ring, said seatcomprising an annular shoulder forrned on the outer surface of the bodyand facing in the direction toward the larger diameter end of the body,said shoulder lying at right angles to the axis of rotation of the body,and a hollow frusto-conical grinding ring the smaller diameter end ofwhich rests on said seat and said ring fiaring radially outwardly fromsaid seat toward its larger diameter end, the body having a part theretothat extends from the shoulder to the larger diameter end of said bodyand said part receiving the inner surface of the grinding ring andsupporting said grinding ring over a major portion of its axial length,the outer surface of the body having a plurality of circumferentiallyspaced grooves each extending radially outwardly to and terminating atthe shoulder.

3. A grinding wheel comprising a hollow frusto conical supporting bodyhaving means at the smaller diameter end for mounting the same forrotation about the central longitudinal aXis of the body, the largerdiameter end of the body having a radi ally extending seat for agrinding ring, said seat comprising an annular shoulder formed on theouter surface of the supporting body, said shoulder extending from theexterior of the body towards the interier thereof, and a hollow frustoconical grinding ring the small diameter of which rests on said seat andsaid ring fiaring radially outwardly from said seat towards its largerdiameter end and said ring being backed at its inner frusto conicalsurface to a major portion of the axial length of its frusto conicalsurface by the part of the supporting body that extends from the seat tothe larger diameter end of the body, said ring being of abradablematerial terminating wat its larger diameter end in a grinding surface,the ring being of substantially smaller mass than the mass of thesupporting body, and the portion of the supporting body between the seatand the outermost larger diameter end thereof being of plastic materialthat may be progressively dressed away as the grinding surface of thegrinding ring is progressively worn whereby the edge of the supportingbody at the larger diameter end thereof may be maintained in reinforcingposition immediately adjacent to the grinding surface thereof during theprogressive wearing away of the ring, said body having formed in itsouter surface a plurality of circumferentially spaced grooves thatextend from said smaller diameter end and terminate at said shoulder andbeing effective by rotation of the body for accentuating a movement ofcooling air against said seat.

4. A grinding wheel comprising a hollow frusto conical supporting bodyhaving means at the smaller diameter end for mounting the same forrotation about the central longitudinal axis of the body, the largerdiameter end of the body having a radially extending seat for a grindingring, said seat comprising an annular shoulder formed on the outersurface of the supporting body and extending from the exterior of thebody towards the inten'or thereof, and a holiow frusto conical grindingring the smaller diameter of which rests on said seat and said ringflaring radially outwardly from said seat towards its larger diameterend and said ring being backed at its frusto conical surface to a majorportion of the axial length of its frusto conical surface by the part ofthe supporting body that extends from the seat to the larger diameterend of the body, said ring terminating at its larger diameter end in agrinding surface, the ring being of substantially smaller mass than themass of the supporting body, and the portion of the supporting bodybetween the seat and the outermost larger diameter end thereof being ofplastic material that may be progressiyely dressed away as the grindirgsurface of the gn'nding ring is progres:

sively worn whereby the edge of the supporting body at the largerdiameter end thereof may be maintained in reinforcing positionimmediately adjacent to the grinding surface thereof during therogressive wearing away of the ring, said body having a plurality ofgrooves in its outer surface that extend from the seat toward saidsmaller diameter end of the body for accentuating a movement of coolingair against said seat.

5. A grinding wheel comprising a hollow frusto conical body having meansat the smaller diameter end for mounting the same, a frusto conicalgrinding ring located on the outer surface of said body at the largerdiameter end thereof and backed'at its inner surface by the frustoconical surface of the body over a major portion thereof, and coolingmeans on the outer surface of said body for accentuating a movementalong the outer frusto conical surface of the grinding ring, saidcooling means including Channels in said outer surface that terminate atthe juneture of the grinding ring and body.

6. An abrasive grinding wheel comprising a hollow frusto-conical bodyhaving means at its smaller diameter end for mounting the same, agrinding ring seat formed at the outer circtunference of the largerdiameter end of the body, and a frusto conical grinding ring resting onsaid seat and reenforced by being backed at its inner frusto conicalsurface'by said body to a major extent of the outer frusto conicalsurface of said ring, said ring including a diamond ab rasive and saidbody belin of plastic so that as the ring is progressively worn away thebody may be progressively dressed away while maintaining itsreenforcement around the ring up to the region of the abrading workingsurface of the ring, the portion of the body that extends between theabrasive member and the means for mounting the body being substantiallya surface of revolution centered on the wheel axis but deviating from asurface of revolution by having means forming radially out- Wardlyopening Channels along the surface and each channel extending to thejuncture of the abrasive member with the body for accentu ating motionof cooling air along the outside of the frusto conical body towards theradially outermost edge of the outer frusto conical surface of thegrinding ring.

7. A grinding wheel comprising a hollow body having means at one endthereof for mounting the body for rotation about the centrallongitudinal axis of the body, said body also having an outer frustoconical surface surrounding said aXis and terminating at its largerdiameter end at the other end of the body, said surface terminating atits smaller diameter end in an annular shoulder concentric with saidaxis, and `a frusto conical grinding ring the small diameter of whichrests on said shoulder, the inner frusto conical surface of said ringbeing backed by the part of the body having the frusto conical surfaceand said part of the body extending over a major portion of the innerfrusto conical surfacetof the ring to reinforce the ring up to theregion of the working surface thereof, said frusto conical body surfacehaving a plurality of circumferentially spaced radially outwardlyopening grooves that terminate at said shoulder for accentuating themotion of cooling air along said frusto conical body surface toward saidshoulder.

References Cted in the file of this patent UNITED STATES PATENTS ToneIan. 10, 1939 Whting L Jan. 5, 1943 Lindblad June 28, 1960 i FOREIGNPATENTS Canada u Sept. 11, 1956

1. A GRINDING WHEEL COMPRISING A BODY HAVING MEANS FOR MOUNTING SAME FORROTATION ABOUT THE CENTRAL LONGITUDINAL AXIS OF THE BODY, MEANS ON SAIDBODY FORMING A SEAT SURROUNDING SAID AXIS, AND AN ABRASIVE MEMBER ONSAID SEAT, THE PORTION OF THE BODY THAT EXTENDS BETWEEN THE ABRASIVEMEMBER AND THE MEANS FOR MOUNTING THE BODY BEING SUBSTANTIALLY A SURFACEOF REVOLUTION CENTERED ON SAID AXIS BUT DEVIATING FROM A SURFACE OFREVOLUTION BY HAVING MEANS FOR DIRECTING A FLOW OF COOLING AIR AGAINSTTHE ABRASIVE MEMBER, SAID FLOW DIRECTING MEANS COMPRISING CHANNELS INTHE SURFACE OF REVOLUTION AND EACH CHANNEL EXTENDING TO THE JUNCTURE OFTHE ABRASIVE MEMBER WITH THE BODY, AND DIRECTING A FLOW OF AIR TOWARDSAID JUNCTURE FOR ACCENTUATING MOTION OF COOLING AIR AT THE REGION OFSAID JUNCTURE.